US3095986A

US3095986A - Blast furnace tops

Info

Publication number: US3095986A
Application number: US67386A
Authority: US
Inventors: Francis J Sines
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1960-11-04
Filing date: 1960-11-04
Publication date: 1963-07-02
Anticipated expiration: 1980-07-02

Description

July 2, 1963 F. .J. SINES BLAST FURNACE TOPS 4 Sheets-Sheet 1 Filed Nov. 4. 1960 Z25 M/Ef M13 ATTORNEY y 1963 F. J. SINES BLAST FURNACE TOPS 4 Sheets-Sheet 2 Filed Nov. 4, 1960 I N V EN TOR. FRANCIS J. S/NfiS ATTORNEY July 2, 1963 F. J. SINES 3,095,986

BLAST FURNACE TOPS Filed Nov. 4, 1960 4 Sheets-Sheet 3 0C POM/5Q INVENTOR. FIQl/VC/S J. SIA/Efi A 7' TORNEY July 2, 1963 F. J. SINES BLAST FURNACE TOPS Filed Nov. 4, 1960 4 Sheets-Sheet 4 0 was M0 as 066 INVENTOR.

Fig.5

ATTORNEY United States Patent 3,095,986 BLAST FURNACE TOPS Francis J. Sines, Youngstown, Ohio, assignor to United States Steel Corporation, a corporation of New Jersey Filed Nov. 4, 1960, Ser. No. 67,386 9 Claims. (Cl. 2l435) This invention. relates to blast furnace tops and more particularly to charging equipment for blast furnace tops. Among the functions which a blast furnace top must perform are the sealing of blast furnace gases so that they cannot escape into the atmosphere and the distributing of the charge uniformly over the stockline in the stack of the furnace. At present, these functions are performed by the well-known bell and hopper structure. That structure has certain disadvantages, however. The bells are large and expensive and require complex equipment for their operation. Also, the construction is such that the sealing surfaces are subject to abrasion from the blast furnace gas. Because these bells must be located over the center of the column, the gas from the furnace must be removed by upstakes which are placed at the periphery of the furnace. The cross-sectional area of these uptakes is therefore limited with the result that the gases must be transmitted at such a high velocity that large dust particles are carried through the uptakes. Thus, before the gas is used, the dust must be removed by large and expensive dust catchers. My invention alleviates these disadvantages by eliminating the bells and hoppers and by placing the uptake above the center of the furnace so that its area may be greatly increased. For example, I have found that I can triple the uptake area and thereby decrease the velocity of the gas to /3 its former value. Because the diameter of the largest sized airborne particle varies approximately with the square of the gas velocity, a reduction of the velocity to /3 its former value causes a reduction in the diameter of the maximum sized particle to ,4, its former value. Thus, the dust catcher may be eliminated and the gas washing facilities reduced in size.

Therefore, it is an object of my invention to provide a an improved blast furnace top which eliminates the usual bell and hopper arrangement and the complicated mechanism necessary for its operation.

Another object is to provide a blast furnace top which has an uptake of sufiiciently large area to reduce the size of dust particles which are carried out of the furnace with the blast furnace gases.

These and other objects will be more apparent after referring to the following specification and attached drawing, in which:

FIGURE 1 is a vertical cross section view of a blast furnace top made in accordance with my invention;

FIGURE 2 is a cross section taken on the line IIII of FIGURE 1;

FIGURE 3 is a detailed cross sectional view of my charging hopper and gas seal;

FIGURE 4 is a schematic diagram of the control circuit for the operation of the charging hopper; and

FIGURE 5 is a schematic diagram of the control circuit for the distributor doors used in practicing my invention.

Referring more particularly to the drawings reference numeral 1 indicates the upper part of a conventional blast furnace with the stockline being indicated by the letter L. A steel shell 2 is attached to the top of furnace 1 in any conventional manner which will prevent leakage of gas. The top of the shell 2 is closed and is provided with a conventional bleeder 4. The lower portion of the inside surface of the shell 2 is provided with a wear plate 6 with refractory bricks 8 being provided between the shell 2 and the Wear plate 6. The shell 2 is provided with an opening 10 through which the charge is introduced in a manner to be described hereinafter. The shell 2 also has an opening 12 through which the exhaust gases pass to a conventional downcomer 14, and an opening 16 through which dust particles pass to a dust pipe 18. A cylindrical uptake 20 is supported concentrically within the shell 2. The inner surface of the uptake 20 is lined with refractory material 22. The uptake 20 is provided with openings 24 for the release of the exhaust gases. In the annular space between the shell 2 and the uptake 20 is a slanted distributor chute 26 formed by an upper elliptical member 28 and a lower elliptical member 30. The chute 26 extends through the opening 10 and is provided with a dividing structure 32 (FIGURE 2) which is located in the path of flow of the raw materials to divide the charge equally between the two sides of the chute 26. The lower member of the chute 26 is provided with four

openings

34, 36, 38 and 40 through which the raw materials are discharged. An auxiliary chute 42 is located below the opening 34 and has openings 43 and 44 therein, the latter of which is diametrically opposite opening 38. An auxiliary chute 46 is located below the opening 40 and has openings 47 and 48 therein, the latter of which is diametrically opposite opening 36. The side walls of the chutes 26, 42. and 46 are formed by the shell 2 and the uptake 20. A door 50 associated with

openings

34 and 43 is attached to a shaft 52 which is rotated through a gear 54 and a pinion 56 attached to the shaft of a motor 58. In like manner, a door 60 associated with openings 40 and 47 is attached to a shaft 62 which is rotated through a gear 64 and a pinion 66 attached to the shaft of motor 68. At the top of the chute 26 and exterior to the shell 2 is a housing 70 in which a charging hopper 72 is arranged to rotate. The charging hopper 72, having a counterweight 73, is attached to a shaft 74 which is rotated through a gear 76 driven by a pinion 78 mounted on the shaft of a motor 80. Rods or bearings 81 are mounted on the outside of hopper 72. Supported on the housing 70 are doors 82 and 84 (FIG- URE 3) which are attached to and rotate with

shafts

86 and 88, respectively. C-ounterweights 90 and 92 are mounted on

shafts

86 and 88, respectively. The counterweights 90 and 92 are of such weight and are so positioned that the

doors

82 and 84 are normally biased to closed position. A flange 94 is attached to the housing 70 and is adapted to provide a gas tight seal with door 82 when it is in its closed position. A flange 96 is simi larly attached to the housing 70 to provide a gas tight seal with door 84. A skip bridge 98 and skip car 100 are provided for carrying the charge up to the hopper 72. The skip car 100 is provided with an arm 102 (FIG- URE 4) which is preferably made of a flexible material. A relay 104 having a normally open contact 104C and a normally closed contact 104C1 is mounted on the skip bridge and is situated with respect to the arm 102 so that the arm 102 will open the contact 104C each time the skip car descends but the arm 102 will not affect the relay 104 on the upward trip of the skip car. One terminal of the relay coil 104 is connected to the contact 104C and the other terminal is connected to ground. A DC. power source 106, 108 has its positive terminal connected to one terminal of the motor 80 through the contact 10'4Cl and a normally closed contact 116C of a relay 110. The relay 110 also has normally closed contact 110C1 and normally open contacts 110C2, 110C3, 110C4, and 110C5. The negative terminal 108 is connected to the other terminal of the motor 80 through the contact lltlCl. Normally open switches 112 and 114 are provided for operation by movement of hopper 72, the switch 112 being closed when the hopper is in its dumping position and the switch 114 being closed when the hopper is in its loading position. The terminal 106 is also connected to the relay coil 104 through the contact 104C, to relay coil 104 through switch 114 and contact 110C2, to relay coil 11!} through the contacts 104C1 and 110C5, and to relay coil 110 through switch 112. A normally open switch 116 (FIGURE is mounted on the skip bridge 98 so that it will be momentarily closed by the arm 102 each time the skip car 100 ascends. The positive terminal 118 of a direct current power source is connected to the coil of a relay 120 through the switch 116. The relay 120 has normally open contacts 120C, 120C1 and 120C2. A relay coil 122 is connected to terminal 118 through contact 128C and has normally open contacts 122C, 122C1 and 122C2. A relay coil 124 is connected to terminal 118 in series with contacts 120C1 and 122C1 and has normally open contacts 124C, 124C1 and 124C2, and normally closed contacts 124C3 and 124C4. A relay coil 126 having normally open contacts 126C and 126C1 and normally closed contact 126C2 is connected to terminal 118 through

contacts

126C and 128. The contact 128 is normally closed and will be opened only when the door 60 is in its lowest position due to the action of an arm 130 which is arranged to rotate with the door 60. Power may also be supplied to relay coil 122 through contacts 126C2 and 122C. Power may also be supplied to relay coil 124 through contacts 126C2 and 124C. Power may also be supplied to relay coil 126 through contacts 120C2, 122C2, and 124C1. Power is supplied to the motor 58 through normally open contact 132C of a relay 132. The coil of relay 132 is energized through contacts 126C2, 122C, 124C4 and 134. The contact 134 is normally closed and is opened only when the door 50 is in its highest position by action of an arm 136 which is arranged to rotate with the door 50. Power is supplied to the motor 68 through normally open contact 1380 of a relay 138. The coil of relay 138 is energized through contacts 124C2 and 140 or through contacts 126C2, 122C, 124C3 and 142. The

contacts

140 and 142 are normally closed and are opened by the arm 130 only when door 60 is at its highest position or intermediate position, respectively. A member 144 is secured to shaft 52 for rotation therewith and is provided with teeth 144A and 144B. A pivoted pawl 146 is arranged to engage the teeth 144A and 1448 when the door 50 is in its highest and intermediate positions, respectively. An electromagnet 148 is provided to release the pawl 146 from engagement with the teeth 144A and 144B and is energized through contacts 120C2 and 122C2. A member 150 is secured to shaft 62 for rotation therewith and is provided with teeth 150A and 15013. A pawl 152 is provided to engage the teeth 150A and 150B and an electromagnet 154 is arranged to disengage the pawl 152 from the teeth 150A and 15013. The electromagnet 154 is energized through the contact 126C1.

The operation of my device is as follows:

With the hopper 72 in its upright position (FIGURE 4) it is ready to receive a charge from the skip car 100 and the door 84 is closed so as to seal in the blast furnace gases. After the skip car 100 has dumped its load into the hopper 72 it will descend and the arm 102 will open contact 104C and close contact 104C1. Power will thereby be supplied to the motor 80 through contacts 104C1, 110C and 110(31 so as to dump the hopper 72. As the hopper 72 rotates the door 82 will close against flange 94 due to the counterweight 90 before the door 84 begins to open so as to provide a continuous seal between the interior of the furnace and the atmosphere. When the hopper 72 reache the dumping position the contact 112 will be closed and the relay coil 110 will be energized closing its contacts 110C3 and 11003 so as to reverse the polarity of the power supplied to the motor 80 to return the hopper 72 to its upright position. The relay coil 110 will be locked in through contacts 110C5 and 104C1 during this time. When the hopper 72 reaches its upright position the contact 114 will close to energize relay coil 104 through contacts 114 and 110C2.

This locks in relay 184 through contact 104C, preparing it for the next cycle of operation and deenergizing relay through the opening of contact 104C1.

Assuming that the

doors

50 and 60 were in their lowest positions when the hopper 70 was being dumped as described above, the charge will pass down through the chute 26 and will fall straight through the

openings

34, 40, 43 and 47 onto the stockline L in the furnace 1. When the loaded skip car 100 again ascends the skip bridge 98 the arm 102 will momentarily close the contact 116 (FIG- URE 5) which will momentarily energize the relay coil 120. This will energize coil 122 through contact 120C and lock it in through the contacts 122C and 126C2. Energization of coil 122 will energize coil 132 through contacts 126C2, 122C, 12404, and 134, closing its contact 132C to energize motor 58 which will operate to move the door 50 upwardly. This movement will continue until the arm 136 opens the contact 134 at which time the pawl 146 will engage the tooth 144A to hold the door St] in its uppermost position. Energization of coil 122 will also energize coil 138 through contacts 126C2, 122C, 124C3, and 142. closing its contact 138C to energize motor 68 which will operate to move the door 60 upwardly. This movement will continue until the contact 142 is opened by the arm at which time the pawl 152 will engage the tooth 1508 to hold the door 60 in its intermediate position which closes opening 47. With the

doors

50 and 60 positioned as above indicated, the charge dumped into the chute 26 will fall onto the stockline L through the

openings

36 and 48. When the skip car 100 again ascends, the momentary operation of relay 120 through contact 116 will momentarily energize the electromagnet 148 through contacts 120C2 and 122C2 so as to disengage the pawl 146 from the tooth 144A. This disengagement is only momentary so that the pawl 146 will engage the tooth 1448 and stop the door 50 in its intermediate position so as to close opening 43. The momentary operation of relay 120 will also energize coil 124 through the contacts 12tiC1 and 122C1 and the relay 124 will be locked in through the contacts 124C and 126C2. Energization of relay 124 energizes relay 138 through contacts 124C2 and thereby closing contact 138C to connect power to the motor 68. This causes door 60 to rotate upwardly until the contact 140 is opened by the arm 130 at which time the pawl 152 will engage tooth A and hold the door 60 in its uppermost position. With the

doors

50 and 60 so positioned the next charge dumped into the chute 26 will fall through openings 44 and 38 to the stockline L. As the skip car again ascends and the contact 116 is momentarily closed, power is momentarily connected to electromagnet 148 through contacts 120C2 and 122C2 and the pawl 146 is raised so as to permit the door 50 to return to its lowest position. Power is also connected to relay coil 126 through contacts 120C2, 122C2, and 124C1 and the relay 126 is locked in through the

contacts

128 and 126C. The operation of relay 126 opens the contact 126C2 through which the

relays

122 and 124 were locked in with the result that those relays are deenergized. Power is also connected to electromagnet 154 through contact 126C1 and the pawl 152 is disengaged from tooth 150A. The door 60' falls by gravity to its lowest position and when it reaches that position the contact 128 is opened by the arm 130 with the result that the relay 126 is deenergized. The system is now restored to its original condition and is ready for another cycle of operation. Thus it is seen that each charge is distributed through a dilferent pair of openings so that the burden will be distributed uniformly in the furnace. As each load is charged into the furnace the gas loss will be a minimum because only one of the

doors

82 and 84 will be open at any one time.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. in a blast furnace an outer shell mounted on top of said furnace and extending upwardly therefrom, an inner shell arranged concentrically within said outer shell above the stock line of the furnace and arranged for conveying exhaust gases therethrough, a first chute slanting downwardly around said inner shell within said outer shell, said chute having a plurality of openings therein for discharging material therefrom, a second chute slanting downwardly from one of said openings around said inner shell, said second chute having at least one opening therein for discharging material therefrom, means to selectably close at least one of said openings, and means for conveying raw materials through the said outer shell to said first chute.

2. In a blast furnace an outer shell mounted on top of said furnace and extending upwardly therefrom, an inner shell arranged concentrically within said outer shell and arranged for conveying exhaust gases therethrough, a first chute slanting downwardly around said inner shell within said outer shell, said first chute including first and second portions extending peripherally around said inner shell and disposed on opposite sides thereof. said chute having a pair of openings therein one at each side of the bottom thereof and a second pair of openings therein one at each side of said inner shell substantially half way down the length thereof, a second chute slanting downwardly from the second pair of openings around said inner shell, said second chute having an opening therein under each of said second pair of openings, a door associated with each of said second pair of openings and the opening therebe heath, said doors being adapted to close either of its associated openings, said second chute having a pair of openings therein one at each side of the bottom thereof, and means for conveying raw materials through the said outer shell to said first chute.

3. In a blast furnace according to claim 1 in which said conveying means includes a housing, said housing having an opening to the atmosphere and an opening into said first chute, a charging hopper mounted in said housing for movement about a generally horizontal axis, means for moving said hopper between a position wholly within said housing and a position at least partially outside said housing, a first door normally closing the opening to the atmosphere and movable outwardly from said housing, and a second door within said housing on the furnace side of said hopper, said second door closing the opening toward the inside of the furnace when said hopper is at least partially out of said hood.

4. In a blast furnace an outer shell mounted on top of said furnace and extending upwardly therefrom, an inner shell arranged concentrically within said outer shell and arranged for conveying exhaust gases therethrough, means located in the space between said outer shell and said inner shell for distributing raw materials about the periphery of the space, means for conveying raw materials through the said outer shell to said distributing means so arranged as to reduce to a minimum the passage of blast furnace gases through said outer shell. said distributing means including a lower substantially annular member and an upper substantially annular member spaced vertically with respect to one another and with respect to said inner and outer shells to form a slanted chute, means for equally dividing the flow of raw materials from said conveying means, said lower annular member having a first opening located at a point approximately 90 around said annular member from said dividing means, a second opening located at a point approximately 180 from said first opening, a third opening located between said first and second openings and approximately 60 from said second opening, and a fourth opening located between said first and second openings and approximately 60 from said first opening, a first door for closing said first opening, a second door for closing said second opening, a first motor for operating said first door, a second motor for operating said second door, a slanted chute communicating from said first opening to a point approximately from said third opening, and a slanted chute communicating from said second opening to a point approximately 180 from said fourth opening.

5. In a blast furnace according to claim 4 in which said conveying means includes a housing, said housing having an opening to the atmosphere and an opening into said distributing means, a charging hopper mounted in said housing for movement about a generally horizontal axis, means for moving said hopper between a position wholly within said housing and a position at least partially outside said housing, a first door normally closing the opening to the atmosphere and movable outwardly from said housing, and a second door within said housing on the furnace side of said hopper, said second door closing the opening toward the inside of the furnace when said hopper is at least partially out of said housing.

6. In a blast furnace the improvement which comprises, a stationary outer shell mounted on top of the furnace, a stationary inner shell disposed within said outer shell terminating at a gas entry opening above the stock line of the furnace, means to exhaust gas from the inner shell, and distributing means including at least one stationary chute between said shells to receive and distribute raw material in the furnace.

7. The device of claim 6 wherein the chute has a plurality of openings therein communicating with the furnace.

8. The device of claim 7 further characterized by means adapted to close at least one of said openings whereby to regulate the discharge of material from said chute.

9. In a blast furnace an outer shell of substantially circular cross section mounted on top of said furnace and extending upwardly therefrom, an inner shell substantially concentric with said outer shell and located above the stock line of the furnace, means for distributing raw materials located in the annular space between said shells, said distributing means including a chute having a plurality of openings through which the raw materials fall onto the stock line of the furnace, means for conveying raw materials to said distributing, means, said conveying means including a housing having an opening to the atmosphere and an opening into said chute, a charging hopper mounted in said housing for movement about a generally horizontal axis, means for moving said hopper between a position wholly within said housing and a position at least partially outside said housing, a first door normally closing the opening to the atmosphere and movable outwardly from said housing, and a second door within said housing on the furnace side of the housing, said second door closing the opening toward the inside of the furnace when said hopper is at least partially out of said housing.

References Cited in the file of this patent UNITED STATES PATENTS 910,233 Roberts Jan. 19, 1909 1,301,370 Brennan Apr. 22, 1919 1,724,402 Holden Aug. 13, 1929 2,814,478 Van Loon Nov. 26, 1957

Claims

1. IN A BLAST FURNACE AN OUTER SHELL MOUNTED ON TOP OF SAID FURNACE AND EXTENDING UPWARDLY THEREFROM, AN INNER SHELL ARRANGED CONCENTRICALLY WITHIN SAID OUTER SHELL ABOVE THE STOCK LINE OF THE FURNACE AND ARRANGED FOR CONVEYING EXHAUST GASES THERETHROUGH, A FIRST CHUTE SLANTING DOWNWARDLY AROUND SAID INNER SHELL WITHIN SAID OUTER SHELL, SAID CHUTE HAVING A PLURALITY OF OPENINGS THEREIN FOR DISCHARGING MATERIAL THEREFROM, A SECOND CHUTE SLANTING DOWNWARDLY FROM ONE OF SAID OPENINGS AROUND SAID INNER SHELL, SAID SECOND CHUTE HAVING AT LEAST ONE OPENING THEREIN FOR DISCHARGING MATERIAL THEREFROM, MEANS TO SELECTABLY CLOSE AT LEAST ONE, OF SAID OPENINGS, AND MEANS FOR CONVEYING RAW MATERIALS THROUGH THE SAID OUTER SHELL TO SAID FIRST CHUTE.